To develop new techniques for the conversion of functional groups to paramagnetic labels capable of detection by esr spectroscopy. The conversion of conjugated dienes to 1,2- and 1,4- semidiones is being studied by use of the dieneophile vinyl carbonate, the 2 plus 2 cycloaddition reaction with acetoxyketene, and the 1,4-polymeric peroxides. Particular emphasis is being given to the synthesis of the semidiones in the bicyclo (2.2.1)-heptadiene-bicyclo(3.2.0)-heptadiene pair of valence tautomers and for the various valence isomers of cyclooctatetraene 1,2- and 1,4- semidiones.